Study On Deformation Of A Hybrid Rotary Table

With the technological development and social progress,modern machinery manufacturing has been developed rapidly.Manufacturing industries including aeronautics,astronautics and ships have raised higher demands for the accuracy of part manufacturing.As key part of heavy-duty machines,large-scale rotary tables play an important role in the machining precision.However,the load-carrying capacity and machining precision of overseas rotary tables is better than the domestic ones.Under heavy loads and high speeds,temperature rise of oil films and the fluid-solid-thermal interaction between film pressure and the table would cause deformation of the table,influence the shape of oil film and eventually influence the performance of the machine.However,investigation of pressure and temperature distribution of oil films and deformation of the rotary table may help to solve the problem.Based on a hybrid rotary table,the pressure and temperature filed of oil films is analysed by simulations to investigate the effect of oil flow state on the deformation of the rotary table.What this thesis has done is as follows.1.Geometric models of oil cavities and oil films above and below the middle ring are built.ICEM CFD software is applied to mesh the oil film.Governing equations and initial boundary conditions used to solve film flow state are determined.2.Software Fluent is used to simulate the pressure and temperature distribution of oil films,and the simulation results are verified by experiments.The influence of rotating speeds of the middle ring and the oil film thickness on the peak film pressure and temperature is also analysed.The pressure and temperature distribution of oil film below the middle ring is simulated as well3.FEM models of the single cavities on working table and middle ring are established.The fluid-solid interaction between the working table and middle ring is analysed by ANSYS Workbench subsequently.Posing pressure and temperature distribution of oil films on the middle ring,the influence of rotating speeds on the mechanical deformation,thermal deformation and thermal coupling deformation of the working table and middle ring is analysed.The effect of the deformation on the shape of oil films is studied afterwards.4.Considering that the middle ring rotates in the real operation,the pressure and temperature distribution of oil films changes with rotating.Therefore,it is necessary to build FEM models of the whole middle table.The influence of changes in the location of cavities on the thermal coupling deformation of the middle ring under certain conditions are analysed.A test rig is established to test the pressure of oil films below the middle ring to investigate the influence of the shape of oil cavities on the film pressure.